After demuxing ogm: bigger avi

[nexus]

Ok, so here's the story:

I made an avi (without sound): 623MB.
sound: ogg 73,5MB
same sound: lame mp3 70,3MB

muxed:
video + lame: 699MB
video + ogg: 700MB

Because there's no support in VDub etc. for .ogm I wanted to know,
if I can demux the file to work with the avi with VDub later
(for any reason).

I used graphedit to demux the file. Result:

ogg: original: 77.136.083 bytes after demux: 77.136.072 bytes

ok, just a few bytes but:

video: original: 654.058.876 bytes (623MB) after demux: 709.876.736 bytes (676MB)

That's more than a few bytes.

Ok, I remuxed the new video (676MB) with the new ogg and the result:
exactly the same filesize as at the first time =>700MB

Then i remuxed the new video (676MB) with the old lame and I got file
with the exact filesize as the original video (623MB) and lame too=>699MB

So, resumée: there's no problem with muxing, demuxing, remuxing. It
works perfectly. But does anyone now why the demuxed avi is so big?
It seems a bit strange to me.

Oh, the things I used:
DivX 5.02 pro
latest lame and Vorbis codecs
Oggmux v0.85
graphedit

[Sigmatador]

I had the same problem when demuxing an ogm file. i used the avimux filter with graphedit and the file size was bigger than the original one.
to fix that: after demuxing, open your video with virtualdub, chose no audio and video direct stream copy and save to another file. you may obtain the original video file. i suppose avimux filter add an empty audio stream which is remove by the oggmux filter when you remux.

do someone know how to run a direct demux? and is it possible to demux the subtitles ?

[soulfx]

yes, it is possible to demux the subs, all you do is run it throught the subtitle dest filter to a file

and you could probably mess with the filters so it doesn't include a blank audio stream for the avi's, possible use a null terminator.

[Sigmatador]

@soulfx
with subtitle dest filter, the subtitles files are good. thx!
i use ogg muxer to get de ogg audio file, which i can edit with goldwave, play with winamp etc... so i think de file is good
but for the video the only filter can i use is the avi mux, and i have to make a video direct stream copy with no audio after demuxing to obtain de original video file.
which filter do you insert between ogg split and file writer or what do you specify for the avi mux filter?
If i open the avi mux filter options i can see de file size (before i have demux) in the statistic rate box and this is the same than the obtained one before editing with virtualdub. (i hope you will understand my phrases ^^)
thx and bye all ++

[soulfx]

It doesn't seem like the problem comes from a blank audio track, as there is no audio track input into AVImux or output off the AVI Splitter when checking the demuxed video stream output. It doesn't matter in VDub if No Audio is selected or not, because there is no stream anyways, both No Audio and AVI Audio will produce a reduced filesize.

So, really I don't think there is any combination of filters (I could be wrong) to get it to output the actual video filesize from a demux filtergraph. As long as there is a way to get it to work through VDub, you can use that method. It doesn't seem like too big of a problem since everything turns out okay, just the size is off right from a demux (but can later be fixed with Vdub).

Peace,
SoulFX

[Sigmatador]

ok but what's filter is used by vdub to do a direct stream copy with no audio... erf nevermind ^^
another question: is it possible to demux the chapter ? there is no stream for the chapter ...

[soulfx]

You can change/delete/and modify the chapters by running the video stream from Ogg Splitter to the Ogg Muxer, then just bring up the Muxer's properties and there you go.

[Sigmatador]

ok thx ^^